Well I have been on this medication (specifically Wellbutrin XL, the extended release) for about a year.
Despite a couple of very weird mental side effects, once my body had time to adjust (1-3 months, I can't remember) I feel very comfortable knowing that the downward spiral is a little less hard to pull myself out of when it comes back to bother me. Quicksand.
My psychiatrist says the XL is better than SR or the non-extended release versions because it provides continuous protection (LOL, sounds like a diaper or maxi pad, haha) against the depression. I am taking only 150 mg and would recommend that you lower your dosage as much as you can to minimize the anxiety/shaking/nervousness that bothered me at the 300 mg dose.
Another thing- this drug is known to cause strange initial reactions, emotionally- I heard it from my psych as well as 2 different people I know who have been on wellbutrin. Watch out for suicidal preoccupations during the first 2 weeks or so of treatment. If I hadn't known ahead of time that suicidal feelings could occur during the first couple of weeks, it would have been harder for me to resist them. I was preoccupied with death and generally felt much less of an aversion to the physical process of killing myself. Please watch out, all you who start this medication.
One thing my psychiatrist has taught me to do (I am bipolar and on lamictal as well) is increase my dose when I feel an obvious depressive episode coming on. This has happened two times this year and both times a 1-2 day depression subsided after I took double doses of Wellbutrin for a couple of days. Just something to ask your doc about. I hope some of this was helpful! Good luck